Duplex reproduction system

ABSTRACT

An improved duplex reproduction system which produces duplex copy sets in collated separated stacks from a stack of precollated documents. The system includes a document feeding apparatus which feeds a stack of documents one by one onto the platen of a copy processor for producing copies of each document. The copy sheets are transported to a receiving tray in a sorting apparatus which does not sort the copy sheets when producing the first side of the duplex copies. The documents are reloaded into the document feeding apparatus for feeding the documents with the second side onto the platen of the processor. On the simplex or first pass a circuit disables the sorting function of the sorting apparatus. The copy sheets are removed from a single receiving tray of the sorter for a second or duplex run. On the second pass the copies are distributed sequentially to the different trays of the sorting apparatus which is now energized to produce duplex copy sets in separated collated bundles without rearranging or reshuffling of the documents or copy sheets.

United States Patent 1 Drexler et al.

[ Oct. 15, 1974 DUPLEX REPRODUCTION SYSTEM [73] Assignee: XeroxCorporation, Stamford,

Conn.

22 Filed: Aug. 29, 1973 211 Appl. No.: 392,582

[52] U.S. Cl 355/17, 271/64, 355/24, 355/26 [51] Int. Cl 603g 13/00 [58]Field of Search 355/77, 24, 23, 26, 3 R, 355/17; 271/64 [56] ReferencesCited UNITED STATES PATENTS 3,318,212 '5/1967 Rubin 355/3 R 3,506,3474/1970 Carlson 355/3 R 3,580,670 5/1971 Bhagat 355/23 X 3,615,12910/1971 Drawe et al. 355/26 X 3,645,615 2/1972 Spear 355/26 X 3,671,1186/1972 Fantuzzo et al.,.. 355/3 R 3,672,765 6/1972 Altmann .l. 355/243,697,171 10/1972 Sullivan 355/3 R OTHER PUBLICATIONS Duplex CopierIncorporating Sorter Collator," IBM Technical Disclosure Bulletin, Vol.14, No. 5, Oct. 71, pg. 1453.

Primary Examiner-Richard L. Moses [57] ABSTRACT An improved duplexreproduction system which produces duplex copy sets in collatedseparated stacks from a stack of precollated documents. The systemincludes a document feeding apparatus which feeds a stack of documentsone by one onto the platen of a copy processor for producing copies ofeach document. The copy sheets are transported to a receiving tray in asorting apparatus which does not sort the copy sheets when producing thefirst side of the duplex copies. The documents are reloaded into thedocument feeding apparatus for feeding the documents with the secondside onto the platen of the processor. On the simplex or first pass acircuit disables the sorting function of the sorting apparatus. The copysheets are removed from a single receiving tray of the sorter for asecond or duplex run. On the second pass the copies are distributedsequentially to the different trays of the sorting apparatus which isnow energized to produce duplex copy sets in separated collated bundleswithout rearranging or reshuffling of the documents or copy sheets.

4 Claims, 2 Drawing Figures PATENTED I 51974 3.841 .754

SHEET 1 OF 2 s: 52 sa,

FIG. I-

PATENIED 1 51974 3.841.754

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1 DUPLEX REPRODUCTION SYSTEM This invention relates in general to aduplexing system and in particular to an improved apparatus combiningcopier, document feeder and sorter cooperating to produce duplex copiesin collated order from precollated documents without rearranging ofdocuments or copies. The instant application incorporates by referenceU.S. Pat. No. 3,567,214 issued on Mar. 2, i971 on a document feeder andUS. Pat. No. 3,460,824 issued on Aug. 12, 1969 on a sheet sorter eachbeing commonly assigned herewith.

Since the disclosure of the basic concept of xerography, as disclosed inUS. Pat. No. 2,297,691 to Carlson, a variety of machines and deviceshave been proposed to incorporate such teaching in a manner to createcopy xerographically on a commercial basis. For the most part, suchmachines in present commercial use are limited to making a limitednumber of reproductions from an original on one side. It is also knownto produce two sided or duplex copies as described for example in US.Pat. No. 3,615,129. However, there is no document feeder or sorterapparatus to collate copies in accordance with a precollated documentorder. Recently, there has been a demand to produce duplex copies whichcan be .sorted in collated stacks from a precollated order of documentsfed to a platen in a minimum of time without rearranging or reshufflingof documents or copies by the machine operator.

It is an object of this invention to improve copier/duplicator systems.

it is a further object offthis invention to produce duplex copies incollated order from precollated documents in a reliable manner.

It is another object of this invention to print duplex copy sheets incollated stacks in a minimum oftime and without the need for arearranging of documents or copies by a machine operator.

These and other objects of the instant invention are achieved generallyspeaking by a control circuit for feeding documents from a precollatedstack to the platen of thecopier to produce a stack of copies and thenon a second pass separating the duplex copies into separate collatedbundles corresponding to the document order.

For a better understanding of the invention as well as other objects andfurther features thereof, reference is had to the following detaileddescription of the invention which is to be read in conjunction with theaccompanying drawings wherein:

FlG. 1 illustrates schematically a duplex xerographic reproducing systemincluding document feeder and sorter in accordance with the instantinvention; and

FIG. 2 is a schematic electrical diagram of the control circuitaccording to the invention.

As shown schematically in HO. 1 the duplex xerographic reproducingsystem comprises a document feeding apparatus'ZZ, positioned on axerographic processor which transports copy sheets to a sortingapparatus 28. A control panel 32 includes the usual counters and buttonsas well as switch buttons 51 for START PRINT, S2 for sorter ON and S3for document feeder ON. The processor includes a drum shaped surface 40including a photoconductive backing. This surface is mounted on a shaftjournaled in a frame to rotate in the direction of the arrow to causethe drum surface sequentially to pass a plurality of xerographic processing stations.

For the purpose of the present disclosure, the several xerographicprocessing stations in the path of movement of the drum surface may bedescribed functionally as follows:

A charging station A, at which a uniform electrostatic charge isdeposited on the photoconductive layer of the xerographic drum;

An exposure station B, at which a light or radiation pattern of copiesto be reproduced is projected onto the drum surface to dissipate thedrum charge in the exposed areas thereof and thereby form a latentelectrostatic image of the copy to be reproduced;

A developing station C, at which a xerographic developing materialincluding toner particles having an electrostatic charge opposite tothat of the electrostatic latent image are cascaded over the drumsurface, whereby the toner particles adhere to the latent electrostaticimage for a xerographic powdered image in the configuration of the copybeing reproduced;

A transfer station D, at which the xerographic powder image iselectrostatically transferred from the drum surface to a transport sheetmaterial or drum surface;

A'drum cleaning and discharge station' E, at which the drum surface isbrushed to remove residual toner particles remaining thereon after imagetransfer, and at which the drum surface is exposed to a relativelybright light source to effect substantially complete discharge of anyresidual electrostatic charge remaining thereon; and

A fusing station F, at which the powder image is permanently affixed tothe sheet material which is transported to sorting apparatus 28.

For a more detailed description of the copy processing stationsreference is had to US. Pat. No. 3,301,126 to Osborne et al which iscommonly assigned.

In accordance with the present invention a stack of documents are placedin a document feeding apparatus 22 in such a manner as to feed documentsto the platen 50 of the processor. The operation of the document feedingapparatus is such that one document is fed to the platen to produce thedesired number of copies and then advanced from the platen to enable thenext document to be positioned in overlying relationship to the platenas described in the commonly assigned aforementioned patent. The sorterapparatus 28 comprises trays each having a gate 62. ln the first passthe copy sheets are collected in the top tray only as will be describedmore fully hereinafter. After the first side of each document has beencopied the documents are reinserted in the document feeding apparatusand the second side copied. Prior to starting the system for the duplexpass, the copy sheets are returned to the copy sheet feeder section andturned over for receiving copy print on the blank side. It will beappreciated that neither the documents or the copy sheets are rearrangedor inversed to reshuffle the order of the sheets. On the second orduplex pass the copy sheets are distributed sequentially to the trays ofthe sorting apparatus to produce the desired number of collated andseparated duplex sets in a minimum of time.

A better understanding of the invention can be had with a detaileddescription of the operation and reference to the control circuit inFIG. 2. In operation when the system is turned on in the standbycondition a switch S4 is closed to initiate the desired duplexingoperation. When this occurs a relay KX is energized. Upon energizingrelay KX a normally opened contact KX-l is closed and a normally closedcontact KX-Z is opened. Contact KX-l is closed to maintain relay KXenergized and lamp L1 energized indicating the duplex system is on.Contact KX-Z is opened to prevent motor B3 from being energized. MotorB3 is an indexing motor which serves to actuate-gates 62 associated witheach of the trays 60 of the sorting apparatus 28. Start print button S1(FIG. 1) is pressed to energize document on the platen of the processor.Document feeding button S2 and the sorting apparatus button S3 are alsopressed. The processor begins the print cycle and causes a relay KY tobe energized. When the relay KY is energized contact KY-lB opensisolating relay KX from wire 10. It will be noted that relay KX is notdeenergized immediately due to an RC circuit delay comprised of acapacitor C1 and a resistor R1. At the same time a contact KY-lA isclosed connecting relays KX to a wire 47 thereby maintaining relay KXenergized and preventing motor B3 from indexing.

The document feeding apparatus 22 continues to feed documents one at atime onto the platen to produce the desired number of copies which aretransported to the top tray 60 of the sorting apparatus 28. After thelast copy of the last document has been produced, wire 47 isde-energized thereby removing power from both relays KX and KY. Relay KYis coupled with an RC circuit comprised of a capacitor C2 and resistorR2 and a longer delay than does the RC circuit, comprised of capacitorC1 and resistor R1. Asa result relay KX has a shorter delay or dwell forde-energizing than does relay KY which serves to reset the system.

To produce duplex copies the documents are restacked in the documentfeeding apparatus. At the same time the copy sheets are removed fromtray 60 and placed in copy feeding section 65 of the processor with thesecond or blank side turned for receiving the xerographic print. Thestart print button S1 is pressed initiating a normal operation for thesorting apparatus 28 with motor B3 operating in the usual manner toindex the gates. Since switch S4 is not closed motor B3 remain energizedand normal sorting of the copy sheets into the trays of the sortingapparatus occurs. By this structure duplex copy sheets in book form areproduced in collated separated bundles. It will be further appreciatedthat it is not necessary to rearrange or reshuffle the order ofdocuments and/or copy sheets after the first pass or side one copies areproduced and at the end of the duplex reproduction cycle.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in thearth without departing from the spirit of the invention.

What is claimed is:

1. An improved duplex reproduction system producing collated duplex copysets comprising:

document feeding means for feeding a stack of documents in seriatim tothe platen of a copy processor,

copy processor means for copying each document a predetermined number oftimes,

sorter means including a plurality of trays each having an associatedgate at the inlet thereof for opening the tray to receive copy sheetsfrom said processor means,

and

circuit means for disabling said gates on the first pass of copy sheetsthrough said copy processor means to said sorter means and thenenergizing said gates on the second pass to distribute copy sets withoutrearranging documents or copy sheets.

2. A system according to claim 1 wherein said circuit means includesfirst relay means for de-energizing motor means normally operating saidgates and second relay means for resetting said motor means to operatesaid gates sequentially.

3. A system according to claim 2 wherein said first and second relaymeans include RC circuit means, said second relay means having RCcircuit means with a longer dwell time than RC circuit means of saidfirst relay means.

4. A method of producing separated collated duplex copy sets withoutrearranging documents or copy sheets comprising the steps of:

feeding documents in seriatim to the platen of a copy processor toexpose one side thereof a predetermined number of times,

xerographically copying the documents on one side of copy sheetssynchronously advanced through copy processing stations,

advancing the copy sheets to a single receiving tray of a sorterincluding a plurality of trays, refeeding the documents on the otherside to the platen of the copy processor for producing a predeterminednumber of copies thereof,

simultaneously refeeding the copy sheets through the copy processorstations with the blank side turned to receive xerographically copiedimages of the other side of the documents, and

sorting the copy sheets into said plurality of trays sequentially toproduce collated duplex copy sets on the second pass.

1. An improved duplex reproduction system producing collated duplex copysets comprising: document feeding means for feeding a stack of documentsin seriatim to the platen of a copy processor, copy processor means forcopying each documeNt a predetermined number of times, sorter meansincluding a plurality of trays each having an associated gate at theinlet thereof for opening the tray to receive copy sheets from saidprocessor means, and circuit means for disabling said gates on the firstpass of copy sheets through said copy processor means to said sortermeans and then energizing said gates on the second pass to distributecopy sets without rearranging documents or copy sheets.
 2. A systemaccording to claim 1 wherein said circuit means includes first relaymeans for de-energizing motor means normally operating said gates andsecond relay means for resetting said motor means to operate said gatessequentially.
 3. A system according to claim 2 wherein said first andsecond relay means include RC circuit means, said second relay meanshaving RC circuit means with a longer dwell time than RC circuit meansof said first relay means.
 4. A method of producing separated collatedduplex copy sets without rearranging documents or copy sheets comprisingthe steps of: feeding documents in seriatim to the platen of a copyprocessor to expose one side thereof a predetermined number of times,xerographically copying the documents on one side of copy sheetssynchronously advanced through copy processing stations, advancing thecopy sheets to a single receiving tray of a sorter including a pluralityof trays, refeeding the documents on the other side to the platen of thecopy processor for producing a predetermined number of copies thereof,simultaneously refeeding the copy sheets through the copy processorstations with the blank side turned to receive xerographically copiedimages of the other side of the documents, and sorting the copy sheetsinto said plurality of trays sequentially to produce collated duplexcopy sets on the second pass.